Are you sure you didn't? Many companies have language like this buried in the employment agreement (mine does):
I agree to disclose and assign promptly, completely and in writing to the Firm any inventions, whether or not patentable, and including but not limited to, any innovations on processes, methodologies, software applications or products which I discover, conceive and/or
develop, either individually or jointly with others, during the term of my employment with the Firm ("Inventions"). I understand that all inventions which I do hereby assign are and shall become the exclusive property of the Firm, whether or not patent applications are filed thereon, and I agree to treat such inventions as Firm proprietary and confidential information and to use such solely for the benefit of the Firm.